package com.nowcoder.community.service;

import com.nowcoder.community.dao.AlphaDao;
import com.nowcoder.community.dao.DiscussPostMapper;
import com.nowcoder.community.dao.UserMapper;
import com.nowcoder.community.entity.DiscussPost;
import com.nowcoder.community.entity.User;
import com.nowcoder.community.util.CommunityUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Scope;
import org.springframework.scheduling.annotation.Async;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Service;
import org.springframework.transaction.TransactionDefinition;
import org.springframework.transaction.TransactionStatus;
import org.springframework.transaction.annotation.Isolation;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.transaction.support.TransactionCallback;
import org.springframework.transaction.support.TransactionTemplate;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import java.util.Date;

/**
 * @author 黄小白
 * @version 1.0
 */
// 业务层的bean注解
@Service
// 初始化多个实例，默认是单例的，通常默认单例
//@Scope("prototype")
public class AlphaService {
    private static final Logger logger = LoggerFactory.getLogger(AlphaService.class);
    // 业务层调用
    @Autowired
    private AlphaDao alphaDao;

    @Autowired
    private DiscussPostMapper discussPostMapper;
    @Autowired
    private UserMapper userMapper;
    @Autowired
    private TransactionTemplate transactionTemplate;

    // 提供初始化的方法
    public AlphaService() {
//        System.out.println("实例化AlphaService");
    }
    // 构造器之后调用
    @PostConstruct
    public void init() {
//        System.out.println("初始化AlphaService");
    }
    // 销毁之前掉调用
    @PreDestroy
    public void destroy() {
//        System.out.println("销毁AlphaService");
    }
    // 模拟方法
    public String find() {
        return alphaDao.select();
    }


    // 不加括号里面的就默认隔离级别，加上可以进行指定；后面一般还加上他的传播机制
    // REQUIRED: 支持当前事务（外部事物），如果不存在则创建新事物
    // REQUIRES_NEW：创建一个新事务，并且暂停当前事务（外部事物）
    // NESTED: 如果当前存在事务（外部事务），则嵌套在该事务中执行（独立的提交和回滚），
    // 否则就会和REQUIRED一样
    // 通常用的前两个比较多
    // 声明式事务
    @Transactional(isolation = Isolation.READ_COMMITTED,propagation = Propagation.REQUIRED)
    public Object save1(){
        // 新增用户
        User user = new User();
        user.setUsername("alpha");
        user.setSalt(CommunityUtil.generateUUID().substring(0,5));
        user.setPassword(CommunityUtil.md5("123" +user.getSalt()));
        user.setEmail("alpha@qq.com");
        user.setHeaderUrl("http://image.nowcoder.com/head/99t.png");
        user.setCreateTime(new Date());
        userMapper.insertUser(user);
        // 新增帖子
        DiscussPost post = new DiscussPost();
        post.setUserId(user.getId());
        post.setTitle("Hello");
        post.setContent("新人报到");
        post.setCreateTime(new Date());
        discussPostMapper.insertDiscussPost(post);
        // 把abc转换为整数肯定会报错
        Integer.valueOf("abc");

        return "ok";
    }
    // 编程式事务
    public Object save2() {
        transactionTemplate.setIsolationLevel(TransactionDefinition.ISOLATION_READ_COMMITTED);
        transactionTemplate.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED);
        return transactionTemplate.execute(new TransactionCallback<Object>() {
            @Override
            public Object doInTransaction(TransactionStatus status){
                // 新增用户
                User user = new User();
                user.setUsername("beta");
                user.setSalt(CommunityUtil.generateUUID().substring(0,5));
                user.setPassword(CommunityUtil.md5("123" +user.getSalt()));
                user.setEmail("beta@qq.com");
                user.setHeaderUrl("http://image.nowcoder.com/head/999t.png");
                user.setCreateTime(new Date());
                userMapper.insertUser(user);
                // 新增帖子
                DiscussPost post = new DiscussPost();
                post.setUserId(user.getId());
                post.setTitle("你好");
                post.setContent("我是新人");
                post.setCreateTime(new Date());
                discussPostMapper.insertDiscussPost(post);
                // 把abc转换为整数肯定会报错
                Integer.valueOf("abc");
                return "ok";
            }
        });
    }


    // 让该方法在多线程环境下,被异步的调用.
//    @Async
    public void execute1() {
        logger.debug("execute1");
    }

//    @Scheduled(initialDelay = 10000, fixedRate = 1000)
    public void execute2() {
        logger.debug("execute2");
    }
}
